Question: Who is the sibling of Paul Wittgenstein?
Paraphrase: Who is the kin of Paul Wittgenstein?
SPARQL (Wikidata): SELECT ?answer WHERE { wd:Q170348 wdt:P3373 ?X . ?X wdt:P737 ?answer}
Answer: Søren Kierkegaard, Bertrand Russell, Arthur Schopenhauer, Gottlob Frege